Packing for classifiers



Sept. 15, 1936. A DAMAN 2,054,671

PACKING FOR CLASS IFIERS Filed Aug. 6, 1934 Imam/dov A. C. DAMA/v.

Patented Sept. 157 1936 UNITED STATES PATENT OFFICE 10 Claims.

This invention relates to fluid-tight closures for openings around moving machine parts, and it is particularly adapted for use in connection with classifiers in which a moving part of a con- 5 veyor extends through an opening of a container beneath a determinate liquid level. The present application is a continuation in part of my application for patent on Classifiers, Serial No. 581,129, filed December' 15, 1931.

It is an object of my invention to provide a closure of simple construction which is effective under fluid-pressure to close an opening around a moving machine part against the outflow of liquid from a container in which the opening is 15 formed, and further objects reside in the construction of said closure and the cooperative arrangement of parts comprised in the same, as will fully appear in the course of the following description.

In the accompanying drawing, in the several views of which like parts are similarly designated,

Figure 1 is a plan view of a classifier to which the invention is applied,

Figure 2 is a section taken on the line 2-2 of Figure 1,

Figure 3 is an enlarged sectional View of the closure of the present invention as applied to a rotary machine part, and

Figure 4 is a View similar to Figure 3, showing a modified construction of the closure.

Referring more specifically to the drawing, the numeral 5 designates the tank of a classifier having an overflow at 6 to determine the fluidlevel of an aqueous material under treatment.

In the lower portion of the tank, adjacent to its sloping bottom surface, is a conveyor 'I for the movement of solids in the material to a point of deliveryabove the liquid level, and in the construction shown this conveyor comprises a spiral screw blade upon a rotary shaft 8. The shaft projects through an opening 9 in the lower end of the tank beneath' its liquid level, and it is to this opening that the closure of the present invention is applied. In one form of the invention, the closure comprises a sheet I of rubber or other flexible material which covers the opening of the tank and which has a central aperture through which the shaft extends. The flexible sheet constitutes a Wall-member of a box I2 whose body portion is fastened to the wall of the tank exteriorly of the same. The shaft further extends through an aperture of the outside wall of the box, alined with that of the exible wall, and it passes exteriorly of the box, through a stuffing box of conventional construction which provides an additional safeguard against leakage around the shaft. The stufllng box, as shown, consists of a flanged chamber I3 containing a suitable packing I4, and a gland I connected with the flange of the chamber by bolts I6 and engaging the packing. n The box has an opening I'I for the inlet of air or water, it being preferred that the box be filled with a suitable fluid. It is obvious that the box I2 is in effect a part of the tank, which is divided into two compartments by a partition formed by the wall having the opening 9 and by the flexible wall member I0; the latter is therefore positioned in the tank and in contact with the gritty pulp contained therein.

Mounted upon the shaft, inside the box, is a bag I8 of flexible material which is made fluidtight by oppositely extending sleeves fitting snugly around the shaft and held in place by exteriorly applied clamps I9. The bag, Which is of circular form, is adapted to engage with the flexible wall member of the box by internal pressure, and it may be provided with a small opening 20 for the escape of pressure-fluid. The escaping fluid moving to the point of contact of the bag lwith the wall-member functions to remove sand or other matter which might impair or destroy the contact.

The part of the shaft extending through the box is tubular, and it has one or more apertures 2I inside the bag through which a pressurefluid may enter the same.

The end of the shaft is open and connects by means of a hollow fluid-tight head 22 and a tubular conduit 23 with a source of pressure-fluid indicated at 24 in Figure 2 of the drawing.

It will be noted from Figure 2 that the tank 24 is located above the overflow of the classifier tank and that therefore the hydrostatic pressure in the bag I8 and in the box I2 is greater than the corresponding pressure on the upper side of the flexible wall member I0 and therefore the fluid that escapes from the bag flows between the bag and the under surface of the wall I 0 and removes sand or other matter, as pointed out above.

In the operation of the closure, a fluid under pressure, such as air or water, enters the flexible bag and causes it to expand into fluid-tight contact with the flexible wall-member, thereby preventing by its inflation, the leakage of liquid from the tank, around the shaft extending through the opening of the same.

In the modified construction, shown in Figure 4, the hollow bag is replaced by a solid body 25 of flexible material which surrounds the shaft and is held in place thereon by means of a flanged collar 26 and a clamp 21.

In operation, the pressure of liquid in the classification tank forces the flexible wall-member into fluid-tight contact with the flexible body and/or the latter may be pressed into engagement with the wall-member by a pressure-fluid admitted to the box through its opening I1.

What I claim and desire to secure by Letters Patent is:

1. The combination with a container having an opening, and a moving part extending through the opening, of a box exteriorly of the container, having a flexible wall-member covering the opening, a flexible member extending around and secured to the moving part inside the box, disposed to contact with said flexible wall-member by fluid-pressure, means for admitting a iiuid tothe box, and a stuffing box on the first-mentioned box, through which the moving part extends.

2. The combination with a container having an opening, and a rotary shaft extending through the opening, of a box exteriorly of the container, having a wall-member covering the opening, an expansible bag on the Shaft inside the box, disposed to contact the wall-member by inflation, and means for admitting a pressure-fluid to the bag, the bag having an aperture for the escape of pressure-fluid into the box.

3. In a liquid-containing tank having a wall, provided with an opening located beneath a determinate liquid level and a shaft extending through the opening and mounted for rotation, a fluid tight seal for the opening comprising a hollow sealing member of resilient flexible rubber composition secured to the shaft, to rotate therewith, and positioned to engage the outside of the wall about the opening therein, the shaft having an axial opening in communication with the interior of the hollow sealing member, and means for subjecting the interior of the hollow sealing member to fluid pressure to expand it against the outside of the wall.

4. In a liquid-containing tank having a wall provided with a large opening located beneath a determinate liquid level, and a shaft extending through the opening and mounted for rotation, a fluid tight seal about the shaft comprising a flexible wall member having an opening through which the shaft extends, and attached to the wall about the opening therein, a sealing member of resilient flexible material secured tothe shaft to rotate therewith and positioned to engage the outside of the flexible member when the latter is forced outwardly by the pressure of the liquid in the tank, a box forming an extension of the tank and communicating therewith through the openings in the partition and the wall members, and means for subjecting the interior of the box to a fluid pressure greater than the corresponding pressure in the tank.

5. In a liquid-containing tank having a wall provided with a large opening located beneath a determinate liquid level, and a shaft extending through the opening and mounted for rotation, a fluid tight seal about the shaft comprising a flexible wall member having an opening through which the shaft extends, and attached to the wall about the opening therein, and a hollow sealing member of resilient flexible material secured to the shaft to rotate therewith, the shaft having an axial opening in communication with the interior ofthe hollow member, and means for conducting a iiuid under pressure to the interior of the hollow member, through the opening in the shaft to form a yielding surface for engagement with the exible wall member to form a seal when the latter is bent outwardly by the pressure of the liquid in the tank.

6. In a liquid-containing tank having a Wall provided with an opening located beneath a determinate liquid level, and a shaft extending through the opening and mounted for rotation, a fluid tight seal comprising a box positioned exteriorly of the tank and secured to the wall about the opening, the box having its bottom provided with a stuffing box thru which the shaft extends, a sealing member of resilient flexible material secured to the shaft, within the box, and positioned to engage the wall about the opening therein and means for subjecting the interior of the box to a fluid pressure of greater hydrostatic head than the corresponding pressure in the tank.

'7. In a liquid-containing tank having a wall provided with an opening located beneath a determinate liquid level, and a shaft extending through the opening and mounted for rotation, a fluid tight seal comprising a box positioned e'xteriorly of the tank and secured to the wall about the opening, the box having its bottom provided with a stuffing box through which the shaft extends, a hollow sealing member of resilient flexible material secured to the shaft, within the box, and positioned to engage the Wall about the opening therein, the shaft having an axial opening in communication with the interior of the hollow member, the wall of the latter having an opening communicating with the interior of the box and means communicating with the interior of the hollow member through the opening in the shaftfor subjecting the interior thereof and the interior of the box to a fluid pressure of greater value than the corresponding pressure in the tank.

8. In a liquid-containing tank having a wall provided with a large opening located beneath a determinate liquid level, and a shaft extending through the opening and mounted for rotation, a uid tight seal comprising a flexible wall member covering the opening in the wall and provided with an opening for the shaft, an open ended box secured to the outside of the wall and enclosing the opening therein, the bottom of the box having a stuffing box through which the shaft extends, a sealing member of resilient ilexible material secured to the shaft for rotation therewith and positioned to engage the outside of the flexible wall member when the latter is bent outwardly by the pressure of the liquid in the tank, and means for subjecting the interior of the box to a pressure slightly greater than the corresponding pressure in the tank.

9. In a liquid-containing tank having a Wall provided with a large opening located beneath a determinate liquid level, and a shaft extending through the opening and mounted for rotation, a fluid tight seal comprising, a flexible Wall member covering the opening in the wall and provided with an opening for the shaft, an open ended box secured to the outside of the wall and enclosing the opening therein, the bottom of the box having a stuffing box through which the shaft extends, a hollow sealing member of resilient flexible material secured to the shaft for rotation therewith and positioned to engage the outside of the flexible wall member when the latter is bent outwardly by the pressure of the liquid in the tank, the shaft having an axial opening in communication with the interior of the hollow member, the wall of the latter having an opening establishing communication between the interior thereof and the interior of the box, and means connected to the shaft for submitting the interior of the hollow member to a hydrostatic pressure somewhat greater than the corresponding pressure in the tank.

10. The combination with a tank having a transverse partition near one end, dividing it into two compartments, the smaller of which is enclosed on all sides but one, andi forms a pressure chamber, the partition having an opening communicating with the two compartments, a moving part extending through the opening in the partition and through an opening in the outer Wall opposite the partition, a ilexible Wall covering the opening and attached at its edges to the partition, a flexible member extending around and secured to the moving part in the pressure chamber, disposed to contact with said flexible wall member to form a seal, means for admitting a iluid under pressure to the pressure chamber and a stuiling box in the outer wall of the pres- 10 sure chamber.

ARTHUR C. DAMAN. 

